CVE-2026-115557

critical

Description

Python has added a denylist for known compromised certificates to the "ssl" module to ensure user safety even without certificate revocation configured. Known compromised certificates will automatically be rejected regardless of the SSLContext policy configuration.

References

https://mail.python.org/archives/list/[email protected]/thread/FNAJMZV6XQYLVPABNINDMF3VF66AYLW4/

https://github.com/python/cpython/pull/160042

https://github.com/python/cpython/issues/160040

https://github.com/python/cpython/commit/e9bf2cf84eebf838a1edaa1c648c2b36345b99d3

https://github.com/python/cpython/commit/e4f63e65a93cf44c14274aa987e644b8c003625e

https://github.com/python/cpython/commit/e4500d8a437ee5b988a5410cb9b59d177aa01370

https://github.com/python/cpython/commit/e2a9dd97ef9571c710ac0afaa834c8879aebce78

https://github.com/python/cpython/commit/c7fd7edf7e0d122a3973cf676fae21b6aaa650a8

https://github.com/python/cpython/commit/af52b41afa4330fb38583db553631baa2f122f90

https://github.com/python/cpython/commit/a17d9ef549008133eadf20689b1f4787902efe5b

https://github.com/python/cpython/commit/98f0e4ed349f370dc8a00366da1a9797e11c9ed5

https://github.com/python/cpython/commit/7dd8b4736a1419750b94a388e6d158be15836fe6

https://github.com/python/cpython/commit/48d9b2712cd52206c7a5882d0fdca4863ed65e93

https://github.com/python/cpython/commit/36cd295f32fc9ba19399e01abee91231440a41dd

https://github.com/python/cpython/commit/21a50891ab4be2e9955239e625ae2b40c6b1854d

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-109299

https://emudhra.we-have-a-problem.com/

http://www.openwall.com/lists/oss-security/2026/10/24/5

http://www.openwall.com/lists/oss-security/2026/10/20/29

Details

Source: Mitre, NVD

Published: 2026-10-24

Updated: 2026-10-25

Risk Information

CVSS v2

Base Score: 7.5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P

Severity: High

CVSS v3

Base Score: 9.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

CVSS v4

Base Score: 9.4

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

Severity: Critical